1. Technical Field
The present invention relates to a lifting mechanism with support function, in particular to a lifting mechanism which can be controlled to vertically extend/retract and revolve, and can be controlled to adjust its support.
2. Description of Related Art
An office chair with a gas cylinder is an example for devices that have a simple lifting mechanism that allows easy altitudinal adjustment. In a conventional office chair, a seat is connected to a caster-equipped base through a pneumatic device. The pneumatic device is operated by a switch to place the seat at different altitudes that meets various needs in use. However, such a structure can only realize altitudinal adjustment, and does not support displacement in other directions (such as forward/backward or leftward/right displacement), making its use limited.
There is also a mechanism having a post (or a plurality of links) connected to a loading platform (for receiving a keyboard and a monitor) through at least one pneumatic element (such as a gas cylinder). It is such designed that the support force forms the pneumatic element is slightly greater than the overall weight of the loading platform (plus the keyboard and the monitor), so that after the loading platform (plus the keyboard and the monitor) is adjusted to a desired position, it is held at that position and a balanced posture of the whole mechanism is formed. While this structure allows altitudinal and positional adjustment depending on the characteristics of the used post (or the plural links), the balance between the loading platform and the pneumatic element tends to be broken by external force (such as that from a user's palms pressing loading platform when operating a keyboard placed on the) in practical use. When the user operates the mechanism, the loading platform gradually descends; for the reason, the user should use his arm and hand to lift the loading platform, which will result in potential mental pressure; besides, the user may suffer from tendonitis if using the mechanism for a long time, which making it inconvenient to use.
In view of the shortcomings of the known lifting devices, the inventor of the present invention has made improvements thereto and creates the present invention.